Yarn guide control apparatus for a flat knitting machine having a multiple cam system



Oct. 28, 1969 s KUHNERT 3,474,642

YARN GUIDE CONTROL APPARATUS FOR A FLAT KNITTING MACHINE HAVING A MULTIPLE CAM SYSTEM Original Filed Dec. 29, 1964 4 Sheets-Sheet 1 INVENTOR Gottfried KUHNERT Oct. 28. 1969 G. KUHNERT 3,474,642

YARN GUIDE CONTROL APPARATUS FOR A FLAT KNITTING MACHINE HAVING A MULTIPLE CAM SYSTEM Original Filed Dec. 29, 1964 4 Sheets-Sheet 2 s. KUHNERT 3,474,642 YARN GUIDE CONTROL APPARATUS FOR A FLAT KNITTING MACHINE HAVING A MULTIPLE CAM SYSTEM Original Filed Dec. 29, 1964 .4 Sheets-Sheet 5 Oct. 28. 1969 l o I Q I O i n n H F WI IIDIII WH n u u u x m n u o u u u l N E N To R Gottfried KUHNERT B7: I

3,474,642 I NG Oct. 28. 1969 U NERT YARN GUIDE CONTROL APPARATUS FOR A FLAT KNIITI MACHINE HAVING A MULTIPLE CAM SYSTEM 29, 1964 .4 She Original Filed Dec.

INVENTOR. Gottfrled KUHNERT United States Patent M 3,474,642 YARN GUIDE CONTROL APPARATUS FOR A FLAT KNITTING MACHINE HAVING A MULTIPLE CAM SYSTEM Gottfried Kiihnert, Reichenbach, Westhausen, Germany, assignor to Universal Maschinenfabrik Dr. Rudolf Schieber G.m.b.H., Westhausen, Germany Continuation of application Ser. No. 421,939, Dec. 29, 1964. This application Aug. 14, 1967, Ser. No. 660,530 Claims priority, application Germany, Jan. 4, 1964, U 10,394 Int. Cl. D04b 7/04 US. Cl. 6664 10 Claims ABSTRACT OF THE DISCLOSURE Two yarn carrier boxes mounted on a common guide rail in a flat knitting machine are engaged individually or simultaneously by two retractable plungers on the reciprocating carriage. The plungers are controlled by cams on a shifting bar which can be moved on the carriage in the direction of movement of the latter by adjustable abutments on the machine frame when the carriage approaches its terminal position.

This application is a continuation of the copending application Ser. No. 421,939, filed on Dec. 29, 1964, and now abandoned.

The invention relates to fiat knitting machines, and particularly to an apparatus for automatically controlling the yarn or thread guides of a flat knitting machine equipped with a multiple cam system.

The invention will be described hereinafter with reference to a knitting machine having a double cam system, but it is applicable to flat knitting machines having any desired number of cam systems greater than one. A machine on which this invention has been used has been described by me in The Hosiery Trade Journal (Leicester, England, February 1964).

Flat knitting machines of the type referred to usually have a carriage mainly consisting of two cam boxes connected by one or two bows or bridges. Each cam box encloses a dual cam arrangement for cooperation with butted needles in an associated needle bed. The two bow-s also carry a plunger box which is arranged between the bows. Plungers are mounted in the plunger box for longitudinal movement between a retracted and an operative position. In the latter position they engage yarn carrier boxes for actuating movement of the same along guide rails which extend through the bows and are parallel to the direction of carriage movement. The boxes carry the yarn guides proper. It is common practice to arrange two yarn carrier boxes on the same guide rail and to couple them to the carriage singly or jointly (see Flachstrickerei by Kurt Haehnel, Fachbuchverlag Leipzig, 1959, pages 202 and 203).

Movement of the plungers between their retracted and operative positions is actuated in the known knitting machines by shifting bars mounted on the plunger box. The bars are elongated transversely to the direction of cam movement. They have bores or recesses which accommodate the plungers.

When the bars are shifted relative to each other, selected plungers can pass the recesses in the bars under the pressure of helical compression springs and engage the associated yarn carrier boxes. The known arrangement requires as many shifting bars as there are plungers. The several bars are superposed to form a stack. It is necessary to provide two juxtaposed stacks of shifting bars for knitting machines having double cam systems. Each yarn carrier is selectively actuated by one of two plungers. If the yarn carrier is to cooperate with the leading or with the trailing cam mechanism, it is engaged by the plunger actuated by the associated stack of shifting bars whereas the other plunger is retained in its retracted position. If the yarn carrier is to be disengaged from both cam mechanisms, both plungers are held in the retracted position.

The known apparatus is relatively complex. It includes a large number of movable parts which are therefore relatively difiicult to operate and to maintain. The primary object of the invention is the provision of a yarn guide control apparatus which is simpler than the known arrangement, and therefore more easily operated and maintained.

Another object is the provision of a control apparatus which is rugged and not subject to rapid wear, even when employed in a fully automatic knitting machine.

With these and other objects in view, the invention in one of its aspects, provides a knitting machine in which a carriage reciprocate-s on the supporting machine frame between two terminal positions. A plurality of guide rails elongated in the direction of carriage movement is mounted on the support and guides longitudinal sliding movement of respective yarn carrier boxes. A plurality of shifting bars elongated in the direction of carriage movement is mounted on the carriage and movable thereon in a longitudinal direction. Two groups of plungers are guided on the carriage for movement transversely of the direction of carriage movement between respective retracted and operative positions. A plunger of each group is associated with each shifting bar, and the two associated plungers are spaced longitudinally of the bar.

Cam means on each bar engage the associated plungers for moving the same between their aforementioned positions when the shifting bar moves longitudinally on the carriage. The cam means are adapted to hold each associated plunger in the retracted position while the other plunger is in the operative position when the shifting bar is in a first and in a second longitudinal position respectively. The cam means hold both plungers in the retracted position when the shifting bar is in a third position, and both plungers are held in the operative position when the bar is in a fourth longitudinal position. The several positions of the shifting bar are spaced from each other. When a plunger is in its operative position, it engages a corresponding yarn carrier box during reciprocating carrier movement.

Actuating means are provided for moving the shifting bars between their longitudinal positions in response to the reciprocating carriage movement when the carriage approaches one of its terminal positions.

Other features and many of the attendant advantages of this invention will ge readily appreciated as the same becomes better understood by reference to the following detailed description of a preferred embodiment when considered in connection with the accompanying drawing in which:

FIG. 1 shows a control arrangement of the invention in fragmentary bottom plan view;

FIG. 2 shows the apparatus of FIG. 1 in side-elevational section on the line -IIII;

FIG. 3 illustrates the apparatus of FIG. 1 in frontelevational section on the line IIIII-I;

FIG. 4 shows stationary portions of the control arrangement located on the machine frame near the terminal portions of the path of carriage movement in sideelevational section on the line IVIV in FIG. 6;

FIG. 5 shows other stationary portions of the control arrangement in section on the line V-V in FIG. 6;

FIG. 6 is a plan top view of one half of the stationary portion of the control arrangement near one end of the yarn guide rails; and

FIG. 7 shows portions of the control mechanism together with other elements of a knitting machine in front elevation, and partly in section.

Referring now to the drawing in detail, and initially to FIGS. 1 and 7 there is seen the plunger box 1 of the control arrangement which is mounted between the two bows 4 on the carriage 40 of a flat knitting machine of which only a portion of the supporting stationary frame 41, needle beds 42, 43, are shown, and which is equipped with a double cam arrangement 45 conventional in itself. The box 1 movably supports two rows of plungers 2. The rows are spaced in the direction of carriage movement and each row includes eight plungers which are aiigned with the yarn carrier boxes 46 slidably supported on the frame 41 by means of guide rails 47 for movement with the carriage when abuttingly engaged by a plunger. The plunger box 1 also slidably supports eight shifting bars 3 which are elongated in the direction of carriage movement and are each aligned with one of the plungers 2 in each row.

As is better seen in FIGS. 2 and 3, each plunger partly is received in a corresponding bore of the plunger box 1. The free end 30 of each plunger 2 which projects from the bore is flattened so as to present a broad abutment face in the direction of carriage movement for engagement with an associated yarn carrier box, not itself shown in FIGS. 2 and 3, but seen in FIG. 7. Each plunger 2 is formed with a slot therethrough in the direction of carriage movement, and a pin of wear-resistant material is mounted in the plunger so as to extend transversely through the slot.

Each bar 3 movably engages the slots of the two associated plungers 2, and a longitudinal cam face of the bar abuts against the pins 5 under the pressure of helical compression springs 36 interposed between a cover on the plunger box and a recessed annular face of the plunger 2. Two projections 6 on the cam face of each bar 3 have substantially fiat top faces formed with two notches 31 and flanks which obliquely slope from the top face. The notches 31 are dimensioned partly to receive the pins 5. The four notches on each bar 3 are aligned in the direction of carriage movement, and. the spacing of the two innermost notches equals the spacing of the two rows of plungers 2 and of the associated pins 5. The bar 3 fully visible in FIG. 2 is positioned so that the associated two pins 5 are received in the outermost two notches respectively. If the bar moves from the illustrated position toward the right or left, one of the plungers 2 moves from the illustrated retracted position into the operative position under the urging of its spring 36 whereas the other plunger 2 is merely shifted to the other notch 31 of the corresponding cam projection 6. Upon further bar movement in the same direction, both plungers 2 are shifted outward of the box 1 into the operative position in which they are set for engagement with the yarn guide with which they cooperate in a manner known in itself.

The movements of the bars 3 relative to the plunger box -1 are actuated when the carriage approaches the terminal portions of its path by engagement of terminal abutment heads 7 on the bar 3 with stationary stops 9, 10, 24 arranged in groups at either end of the carriage path, as shown in FIG. 4, and spaced from each other in the direction of carriage movement. Each stop 9, 10, 24 is transversely movable toward and away from the path of the associated head.

A rocker 8 is arranged in alignment with each bar 3 at both ends of the carriage path. The rocker is pivotally secured on a shaft 18 which extends over the width of the carriage, as is best seen in FIG. 6, and is fixedly mounted on the machine frame. The rocker 8 has two arms which extend approximately in the direction of carriage movement from the shaft 18 in opposite directions. The stops 9 and 10 are constituted by respective faces of the rocker 8 which are angularly offset relative to the axis of the shaft 18 in such a manner that pivoting movement of the rocker from the inoperative position illustrated in FIG. 4 in a clockwise direction first causes the stop 9 to be positioned in the path of movement of a head 7, and then the stop 10. The latter is nearest the bar 3 when the bar approaches the group of stationary stops, and the stop 24 is farthest.

Cam followers 11, 12 on the two bars of each rocker 8 engage a stepped face of a sliding cam 13 or 14 in such a manner that both followers are in abutting engagement with the cam 14 in all positions of the latter. The rocker 8 is firmly held either in its illustrated inoperative position or in one of its operative positions in which it presents one of the stops 9, 10 to the approaching head 7 of the associated bar 3. The two sliding cams 13, 14 arranged at opposite ends of the carriage path for cooperation with the same shifting bar 3 are connected by a rod 15 for joint movement.

A plate 23 best seen in FIG. 6 is pivotally mounted on a shaft 22 by means of brackets 23a at each end of the carriage path. An edge face of the plate 23 constitutes the aforementioned farthest stationary stop 24. The plate 23 extends across the path of all bars 3 when pivoted clockwise from the inoperative position shown in FIG. 4. Movement of the plate 23 into its operative position is actuated by a cam follower 21 on the bracket 23a, as shown in FIG. 5, and cooperating with a sliding cam 20 or 22a. The cams are respectively associated with the symmetrically arranged plates 23 at the two ends of the carriage path and are connected by a rod for joint movement. The plates 23 are so positioned relative to the path of carriage movement that all bars 3 move the associated plungers 2 into the retracted position when their heads 7 engage the stop edge 24. It will be appreciated that engagement of the heads 7 with the edge 24 is impossible unless the corresponding rocker 8 is in the inoperative position.

Movement of the sliding cams 13, 14, 20, 20a toward the right, as viewed in FIG. 4, is actuated by a Jacquard mechanism in a manner known, for example, from Knitted Outerwear Times (New York, April 27, 1964, page 11). The movement of the sliding cams in the op posite direction is actuated by return springs 19 interposed under tension between the cam 13 and the machine frame. The springs urge the cams toward the positions illustrated in FIGS. 4 and 5 in which all stops are withdrawn from the paths of the heads 7.

The sliding cams 13, 14 may be retained in the positions set by the non-illustrated Jacquard mechanism by means of a locking arrangement evident from joint consideration of FIGS. 4 and 6. A locking plate 17 is pivotally mounted on the shaft 22 by means of integral lugs. A. rail 16 mounted on the locking plate 17 extends across the paths of movement of the several cams 14 which have two saw-tooth shaped projections defining recesses 33. The rail 16 is shaped for conforming engagement with the recesses 33. When the cam 14 is arrested against the restraint of its associated spring 19 by engagement of the rail 16 with one of the notches 33, the stop 9 is operative. When the rail 16 engages the other notch 33, the stop 10 intercepts the head 7 of the bar 3.

The cam 20a which controls the plate 23 is also provided with a cam projection 34 (FIG. 5) which cooperates with a cam projection 35 on the locking plate 17 to pivot the latter out of engagement with the earns 14 when the cam 20a moves toward the right from the position shown in FIG. 5. Further movement of the cam 20a in the same direction causes the edge 24 of the plate 23 to be swung into its operative position.

The apparatus illustrated requires but one shifting bar 3 for actuating movements of two plungers 2 respectively associated with the two non-illustrated sets of cams. The bar may assume four positions relative to the supporting plunger box 1 in which no plunger, either plunger 2, or both plungers present the abutment faces of their free ends 30 to corresponding yarn carrier boxes. The bars 3 are held in the several positions by frictional engagement with the plungers 2 under the pressure of the springs 36. The relatively critical positions of the bars in which one or both plungers 2 are retracted are precisely defined by engagement of the pins 5 with the notches 31 in the projections 6 on the bars 3. The bars are shifted between their positions by the stationary stops, and may be shifted at the end of each stroke of carriage movement. Thus the three useful conditions which can be established by the stops at the left side of the machine are: both yarn carrier boxes coupled to the carriage, neither yarn carrier box coupled to the carriage, or right yarn carrier box coupled to the carriage (the left box being behind during subsequent carriage movement toward the right). Correspondingly the stops at the right hand side of the machine will enable: both yarn carrier boxes to be coupled to the carriage, neither yarn carrier box to be coupled to the carriage, or the left yarn carrier box to be coupled to the carriage (the right box remaining at the right side of the machine during carriage movement toward the left).

While the invention has been described with reference to a knitting machine equipped with a double cam system, it will be appreciated that it is not limited thereto, but is also applicable to the actuation of yarn guide movement in fiat knitting machines having more than two sets of cams in each cam box.

It should be understood, therefore, that the foregoing disclosure relates only to a preferred embodiment of the invention, and that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purpose of the disclosure which no not constitute departures from the spirit and scope of the invention set forth in the appended claims.

What I claim is:

1. In a flat knitting machine having a support; a multiplicity of needles extending in a straight row on said support; a carriage mounted on said support for reciprocating movement along said row; a guide rail extending in the direction of carriage movement; two yarn carrier boxes guided on said guide rail in a path extending in said direction; and coupling means for coupling each of said yarn carrier boxes to said carriage; the improvement in the coupling means which comprises:

(a) a shifting bar mounted on said carriage, said bar being elongated in the direction of carriage movement and being longitudinally movable on said carriage;

(b) two plungers guided on said carriage for movement in a direction transverse of the direction of carriage movement between a retracted position and an operative position;

(1) each plunger when in said operative position extending into said path for coupling engagement with a yarn carrier box;

(2) said plungers when in the retracted position clearing said path; and

(c) cam means on said shifting bar and engaging said plungers for moving the same between said positions thereof when said shifting bar moves longitudinally on said carriage,

(1) said cam means including means for holding each of said plungers in the retracted position while the other plunger is in the operative position when said shifting bar is in a first and in a second longitudinal position respectively, for holding both plungers in the retracted position when said shifting bar is in a third longitudinal position thereof, and for holding both plungers in the operative position when said shifting bar is in a fourth longitudinal position, said first, second, third, and fourth positions being spaced from each other.

2. In a machine as set forth in claim 1, actuating means responsive to the reciprocating movement of said carriage for moving said shifting bar between said positions thereof when said carriage approaches one of said terminal positions.

3. In a machine as set forth in claim 1, each plunger being formed with a slot therethrough in the direction of elongation of said shifting bar, said bar being movably received in the slots of said plungers, and engagement means in each slot for engagement with said cam means.

4. In a machine as set forth in claim 3, said engagement means including a pin member mounted on each plunger in said slot thereof and extending therein transversely of the direction of plunger movement.

5. In a machine as set forth in claim 3, said cam means being formed with a plurality of recesses, said engagement means engaging respective recesses in a plurality of said longitudinal positions of said shifting bar.

6. In a machine as set forth in claim 1, engageable abutment means on said shifting bar and on said support for moving said bar between said positions thereof when the carriage moves relative to said support while said abutment means are engaged, the abutment means on the support including a plurality of stop members spaced in the direction of carriage movement, and control means for selectively moving said stop members toward and away from the path in which the abutment means on said shifting bar moves during movement of said carriage.

7. In a machine as set forth in claim 6, two of said stop members jointly constituting a rocker member pivotally mounted on said support for angular movement between an inoperative position in which said two stop members are withdrawn from said path of the abutment means, and two operating positions in which said two stop members are respectively positioned in said path of the abutment means, said control means including means for moving said rocker member between said positions thereof, and for securing the same in said positions.

8. In a machine as set forth in claim 1, first abutment means on said shifting bar, and two sets of corresponding second abutment means on said support, said set of second abutment means being engageable with said first 'abutment means when said carriage approaches said terminal positions respectively for moving said bar between said positions thereof, each set of second abutment means including a plurality of stop members spaced in the direction of carriage movement, and control means for jointly moving corresponding stop members of each set toward and away from the path of movement of said first abutment means.

9. In a machine as set forth in claim 8, said control means including yieldably resilient means biasing said stop members away from said path of said first abutment means.

10. In a machine as set forth in claim 8, locking means for locking said stop members against movement toward and away from said path.

References Cited UNITED STATES PATENTS 3,247,687 4/1966 Schutzengel 6670 FOREIGN PATENTS 1,118,805 3/1956 France. 1,213,382 10/1959 France.

616,390 7/1935 Germany. 475,618 11/1952 Italy.

W. CARTER REYNOLDS, Primary Examiner U.S. C1. X.R. 66-126 

